Unable to add a service reference – locked/read only

I had the same error – what I found, was that there are problems if you have source control plugin “Microsoft Git provider” selected (my WCF solution was not added to source control!) and you try to add service reference.

1. set source control plugin to None
   • go to TOOLS > Options > Source Control.
2. add service reference
3. set the source control plugin to the original value